In order to ferment milk into yogurt, it needs to mix a yogurt seed culture and to maintain a proper fermentation temperature. If the proper fermentation temperature is maintained in a state where the yogurt seed culture is mixed, the milk becomes a drinkable yogurt state after about 4˜5 hours and becomes an illiquidity yogurt after about 8˜9 hours. If the above time limit is over passed, the yogurt becomes over fermented, so flavor may be degraded.
The conventional yogurt fermenter is configured in a structure wherein a lactic acid bacteria seed culture is mixed in milk and is divided and poured into about ten fermentation cups, and the ten fermentation cups are stored in a heating housing (for example, as disclosed in the Korean Utility Model Application Number 20-2002-0020810). In case of the above-mentioned yogurt fermenter, a huge space is necessary for the storage and use of the fermenter due to the dimension of the housing. Since the housing is heated, the loss of the heat energy may increase, and it needs to inconveniently divide and pour the milk into separate multiple fermentation cups. In addition, it also needs to inconveniently store, in the cold state, about ten fermentation cups each filled with the finished yogurt. Since the about ten fermentation cups occupy a lot of the space of the refrigerator, the use of the space of the refrigerator is inefficient. More inconveniently, it needs to wash and dry and store ten empty fermentation cups and the cap after all the yogurt are eaten.